I. Technical Field
The present invention relates to artificial molar teeth capable of easy arrangement when making a dental prosthetic appliance, and easy chewing at the time of mounting as dentures.
II. Description of Related Art
Arrangement of artificial molar teeth when making a dental prosthetic appliance demand advanced techniques and experiences. It has been particularly difficult to arrange opposed teeth in a proper position relation.
In dentures, in the presence of remaining teeth, artificial molar teeth may not be always arranged at specific positions, and the dentures must be tailored for each patient. It is hence impossible to array artificial molar teeth in a predetermined relation of upper and lower jaws, or array artificial molar teeth side by side. Conventionally, hence, after arranging, the artificial molar teeth are significantly ground, and the surface state is largely changed.
Japanese Patent Application Laid-Open No. 2002-177301 below discloses artificial molar teeth in which a lingual cusp, a buccal cusp, and a fossa are formed on the occlusal surface of maxillary molar teeth, and also a lingual cusp, a buccal cusp, and a fossa are formed on the occlusal surface of antagonist, i.e. opposed mandibular molar teeth. These artificial molar teeth are configured such that at a central occlusal position, the lingual cusp of the maxillary molar teeth occludes and contacts with the fossa of the mandibular antagonist, and the buccal cusp of the mandibular antagonist occludes and contacts with the fossa of the maxillary molar teeth.
In the artificial molar teeth disclosed in Japanese Patent Application Laid-Open No. 2002-177301, occlusal contact occurs in a total of 18 points, 9 points at the left and 9 points at the right. In other words, the number of occlusal contact points is smaller than in the full-balanced occlusion, and there is no occlusal contact with the inclined surface of the buccal cusp as in the full-balanced occlusion. Accordingly, when making dentures, arrangement on the wax alveolar ridge or occlusal adjustment by grinding or the like is easy. When the dentures are used, the dentures are stable without falling over. In mastication efficiency including grinding, biting and cutting of food, a satisfactory occlusion close to the full-balanced occlusion will be obtained. Moreover, changing to a lingualized occlusion can be easily conducted not only when making dentures but also when correcting the dentures.
However, in the artificial molar teeth disclosed in Japanese Patent Application Laid-Open No. 2002-177301, it is required to achieve occlusal contacts between the lingual cusp of maxillary molar teeth and the fossa of mandibular antagonist, and between the fossa of maxillary molar teeth and the buccal cusp of mandibular antagonist, respectively. Therefore, it has been extremely difficult to make dentures for each patient according to the complicated oral cavity environments of patients.